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This invention relates to a method for producing water based coating compositions. More particularly, the invention is directed to an efficient method for producing water based coating compositions that have the ability to form highly scratch and abrasion resistant matte coatings in which crosslinked silicone particles are well dispersed.
Japanese Laid Open (Kokai or Unexamined) Patent Application Number Hei 2-113079 (113,079/1990)/EP 0 365 009 A2 (Apr. 25, 1990), discloses blending crosslinked silicone particles into coating compositions to produce coating compositions that form matte coatings.
Since a uniform dispersion is not obtained when crosslinked silicone particles are blended into a water based coating composition, Japanese Laid Open (Kokai or Unexamined) Patent Application Number Hei 5-9409 (9,409/1993)/U.S. Pat. No. 5708057 (Jan. 13, 1998), teaches a method for preparing water based coating compositions in which crosslinked silicone particles are blended as a waterborne suspension into water based coating compositions.
Japanese Laid Open (Kokai or Unexamined) Patent Application Number Hei 11-140191 (140,191/1999) teaches that waterborne crosslinked silicone particle suspensions of crosslinked silicone particles, nonionic surfactant, ionic surfactant, and water, can be blended into water based coating compositions.
A problem with preparing water based coating compositions using waterborne crosslinked silicone particle suspensions is that the application of the resulting water based coating compositions produces matte coatings that have unacceptable scratch and abrasion resistance.
Therefore, the object of this invention is to provide an efficient method for producing water based coating compositions that are able to form highly scratch and abrasion resistant matte coatings in which crosslinked silicone particles are well dispersed.
In particular, the method involves producing water based coating compositions by the addition to a water based coating composition of a waterborne suspension of crosslinked silicone particles that have an average diameter of 0.1 to 200 xcexcm. Furthermore, the method for producing water based coating compositions is characterized in that the suspension is a waterborne suspension of crosslinked silicone particles afforded by effecting crosslinking of a condensation reaction crosslinkable silicone composition comprising (A) an organopolysiloxane that contains at least two silanol groups in each molecule, (B) a crosslinker, and (C) a condensation reaction catalyst. The crosslinking is effected in the emulsified composition in an aqueous solution of an anionic surfactant.
These and other features of the invention will become apparent from a consideration of the detailed description.